Paulyy

+1
350hp 2.5 or 3L will mop the floor with a 250hp 1.8L

V2Rocket

the MWR guys mention a lot how building a 1.8 up to 400hp for racing is much more economical than building a 944 2.5T to 400hp for racing say 100 hours.

tuning, turbo, exhaust, MAF/MAP combos exist to get the 944T to 400hp (LR 340whp kit, $4k), but what are the critical durability mods aside from preventative maintenance (rod bearings, cured by the MM rod mod?)
disregarding the rest of the car build (suspension and stuff), just engine parts.

Cloud9...68

You guys are correct about the fact that how fast the car will be around the track depends a lot on the shape of the power and torque bands produced by the engines. I pulled up a few dyno charts for some 944 turbo and Audi 1.8T producing comparable comparable levels of hp and torque, and the shapes of the curves weren't very different. Here's an article buy a guy who had a MWR build done on his 944:

http://s3mag.com/motor-werks-racing-...d-porsche-944/

These engines can produce stupid levels of power, apparently with good reliability. Again, to me, the weight is the overwhelming advantage of the 1.8T route. I do most of my driving on a tight, technical track, and even with modest power levels, the thought of dropping 150+ pounds out of the front of my car is intoxicating. As is the vision of no more 12-hour belt replacements. But I am glad to see there are so many enthusiastic supporters of the 944/968 engine - hopefully there will be a good market for my 3.0 liter when I swap it out for a 400 hp 1.8T!

Droops83

I agree, and I likely would have already gone this route with my 951 if it weren't for CA smog rules. I love the characteristics and torque of the 944 engine on the street, but it is large and heavy for what it is, and a complete PITA to work on in 951 form (I work on Porsches for a living, and the 951 is among the highest labor times of any P-car for a number of jobs). Plus, it is relatively difficult and expensive to make them reliable in a 400+ hp track application. I'm not sure how the 1.8T would fare, but I am willing to try at this point . . . . we have a dead 931 on our lot that will probably be used as a guinea pig for this swap, if myself or my boss ever find the time and energy to do so!

I am not trashing the 944/951 engine by any means, but it has its limitations (hence all of the LS swaps). The 1.8T and VAG 5-cyl swap ideas are quite intriguing. I give MWR props for capitalizing on the idea and constructing some amazing-looking cars, but I'm not sure I'm willing to pony up $1.6K+ for a bell housing adapter and flywheel . . . . but we shall see!

V2Rocket

I think you should weigh a ready to run 944 engine vs a ready to run 1.8T engine, and you'll find the weight difference to be much less than 150 lbs.
Still significant savings, and behind the axle, but I think that's a "fudged" number to make the swap look better.
Figure accessories (AC, alt, PS, etc) are all roughly the same from one engine to another give or take a few lbs.

What's a 1.8T long block really weigh?

A 944 8v long block (block crank rods pistons head oil pan camshaft+housing) is right around 250lbs.
A 16v long block in similar state will be about 40lbs more.

Droops83

I wouldn't doubt that the MWR claim is slightly fudged, but a 944 engine with intake/exhaust and accessories weighs a lot more than 250 lbs (951 with everything is close to 400#, if not more). It has what could be the world's heaviest (but most robust) automotive 4-cyl crankshaft, and it has large/heavy balance shafts, plus it is physically quite large being open-deck with wide water jackets.

I'd love to keep the 944-based engine in my 951, but after almost 10 years of running it on the track in 100% bone-stock form, I want more power (400-ish would be nice), and I want it to be reliable. My tired original engine (170K on the bottom end) feels pretty quick with the VEMS and trick new Evergreen K27 hybrid turbo, but I don't think it'd last long doing 30+ minute track sessions on a hot day, no matter how well-tuned it is (think cylinder movement). There are a number of smart/resourceful guys on this forum who have struggled to make their modified 951 engines last on track. It certainly can be done with enough time/money spent, but I don't know if I am willing to spend the coin to do so if more modern alternatives are available. My car is a fun street/track car, and I don't need to stick to any particular set of class rules with restrictions on engine type. LSx is tempting but too obvious. The idea of taking 100+ lbs off the nose and moving weight distribution rearward is intriguing, and the easier serviceability would be icing on the cake . . . . but it would be nice if any of these fancy MWR 1.8T cars actually ran in any meaningful club race series to see if there is any substance behind their claims!

333pg333

Not sure I can remember a dyno sheet from these guys. They're a bit notorious for not answering questions. Certainly they look to do good work but remember that they take 924 shells and cut away a ton of car to produce these really light 'specials'. You wouldn't do this to a road car so not really easy to compare apples to apples. As for the motors, can't see them having much tq so if you were contemplating replacing a 3L Porsche motor or even the 2.5L, you'd lose something in tq and driveability on the street. On a track car, perhaps you can compensate a bit. I'd imagine these iron blocks can take a fair bit of boost.

Paulyy

I can already see the problem comparing a built 944 motor vs the 1.8t.

400hp on a 1.8t and they're using turbos like Borgwarner EFR series turbos and you guys are still bolting on K27's to make power... Bolting on a EFR or a GTX series turbo to a 944 2.5 or 3L is a lot different than using the K series turbos or the old T04E stuff.

But Pauly, you need to change the crossover pipe to do that.
But you need to swap a whole engine to get an EFR on a 1.8L + a new set of headers.

Humboldtgrin

MAGK944

Humboldtgrin

Droops83

I agree with you in terms of modern turbos and exhaust setups (I went with a K27 frame so that my factory catalytic converter would still bolt on for California emissions/smog testing purposes), there are a lot of great turbo options out there.

But, my main point above was not turbocharger choice or even ultimate power/torque capability, but durability during sustained track use with higher boost levels. It is no secret the cylinder movement/head gasket sealing is a major issue with the open-deck 944 engine. One could spend big bucks and get a deck plate and larger studs, but when a 944 engine starts costing almost as much to build as an air-cooled 911 engine, then some of the point is lost.

I'm sure the 1.8T has its own issues, but those engines are cheap and plentiful and have good aftermarket support. The main point is, it has a stout little iron block that from all indications can handle a lot of boost, not to mention modern cylinder head/combustion chamber design (don't need to spend big bucks for increasingly rare 16V 944/968 stuff) and easier service while installed in the car.

I have really been rooting for guys like Patrick who have been taking the the 944 engine to uncharted territory, but I simply don't have that kind of coin, and after a certain point other alternatives look better and better . . . . . though it is very unlikely that a performance 1.8T engine could be made CA BAR legal . . . . .

333pg333

All of them use the 968 block save for the Thor motor. Sure, they're not using stock rods/pistons but nor would you if the 1.8lt was 25-30 years old. Nor would the race car versions of these A4 motors be using stock components.
Not saying the 944/68 series motors are the be all and end all. Definitely not. Just comparing cubic capacity as much as anything. Surely these A4 guys are boring them out to 2.2ltr or something??

Paulyy

To build a 944t to get around 400rwhp for a track day with out breaking bank to much
- Pistons
- Rods considering MM bearing mod.
- Modern turbo (Garret GTX series) T04Es are not modern. (you'll need an adapter for it and modify the oil drain housing)
- Headwork (Port work at least)
- Modded Xover for turbo
- Wastegate
- Flash tune at minimum.
- Fuel mods (injectors, fuel pump ect)
- Stock IC will go better with modded end tanks.

To build the 1.8.
You're going to need the same stuff!! Plus the engine, plus the mounts and adapters. You also need a standalone (more money!!!)

Droops83

Hi Pauly,

I know that a 1.8T would have to be built similarly above stock to reach the same power levels, but that is not the point. The 944 is an open-deck engine, and at a certain power level this becomes a major concern in terms of cylinder movement during periods of sustained heavy load, with the resultant cylinder/head gasket sealing issues. A good tune (I already have VEMS standalone engine management and larger fuel pump/injectors installed) and careful management of coolant/oil temps will mitigate this to a certain extent, but at some point the laws of physics and thermodynamics will prevail. The open-deck Subaru WRX engines have the exact same issue. Sure, there are solutions to this such as deck plates and machining for larger-diameter head studs, but this gets expensive (though tracking any 400-hp car won't be cheap!), and you are still dealing with a large, heavy engine with 35+ year old technology. 16V 944/968 components are becoming increasingly rare and expensive, and at some point it makes sense to go with something more modern.

My own '86 951 has probably 10-12K track miles and 170K total miles on the bottom end, with zero mechanical issues, but it was 100% bone-stock the entire time. I changed the rod bearings once as a preventative measure and the originals looked almost new. But, after years of getting passed on straights but out-handling newer Porsches on track, I want to be fast on both parts (my suspension is quite well-developed). My engine needs a rebuild, and I am balking at what it would cost to build a RELIABLE 400+ hp 944 engine for track use (not just occasional bursts on the street, HUGE difference).

I am not trying to hold up the VAG 1.8T as the ultimate solution (I will fully admit that I do not have much experience with them except for a couple of stock rebuilds at my shop), but it does seem to be a solid foundation to build upon, which is why I am seriously considering it. We have a dead 931 on my lot that will probably used as a guinea pig for fitment/layout (keeping in mind the fuel/electrical system differences between the 924 and later 944), and go from there. My VEMS ECU will control it (or most other engines) with ease, and there are a lot of off-the-shelf parts available for the 1.8T (head studs, rods, pistons, etc), and the block can be machined by any competent machine shop (no sleeving BS).

Anyway, we will see if I ever get around to this, too many other projects at the moment! If I win the lottery I will get one of those Thor 968 engines, I promise!